import java.util.Stack;

class Solution {
    public boolean isValid(String s) {
        Stack<Character> stack = new Stack<>();
        for(int i = 0;i < s.length();i++) {
            char ch = s.charAt(i);
            if(ch =='(' || ch =='[' || ch =='{')
                stack.push(ch);
            else {
                if(stack.empty()){
                    return false;
                }
                char top = stack.peek();
                if(top =='('&& ch ==')'|| top == '['&& ch == ']'|| top == '{'&& ch == '}') {
                    stack.pop();
                }else{
                    return false;
                }
            }
        }
        return stack.isEmpty();
    }
    public static void main(String[] args) {
        Solution solution = new Solution();
        String s = "([])";
        System.out.println(solution.isValid(s));
    }
}

